Action.—This is a type of the pure, simple bitters which contain practically no oil or tannin, are not astringent and have no general effect, but act reflexly upon the stomachic and salivary functions by first irritating the mucous membrane and taste buds of the tongue. This action is quite transitory, so that in administering bitters they should be given immediately before meals. Their effect upon the stomach is to increase local circulatory dilation, a freer flow of gastric juice, increase of mucus, and increased muscular action. On account of the action upon the flow of mucus they should not be administered for too long a period lest gastric irritability and consequent impaired digestion result.

Therapy.—The least irritating and one of the best of the simple bitters and of especial value in atony of the stomach with poor appetite and feeble digestion. It is especially valuable in convalescence from acute fevers and other disorders in which there is lack of desire for food and poor digestion, with pain or without pain, immediately upon eating. After the active stage of cholera morbus, cholera infantum, acute diarrhoea, and dysentery it may be given to promote the appetite and digestion. When desired calumba may be combined with magnesia, bicarbonate of soda, senna, ginger, and aromatics, to meet special indications, particularly when flatulence and constipation are present.

Calumba and the allied bitters should not be given in acute or subacute inflammatory conditions of the stomach, nor during acute fevers, nor when digestion is merely impaired, but the appetite remains good. It is largely ineffectual also when organic disease of the stomach prevents the normal outflow of gastric juice. When given, the small doses are preferable to large ones; and on account of the absence of tannin, iron salts may be given with calumba, if so desired. In some respects calumba resembles hydrastis in its local action, and indirectly, by favoring better digestion, the quality of the blood is improved, hence its value in anemia during convalescence.